In the rapid development of computers many advancements have been seen in the areas of processor speed, throughput, communications, fault tolerance and size of individual components. Today's microprocessors, memory and other chips have become faster and smaller. However, with the increase in speed, reduction in the size of components, and increased density of circuitry found within a given chip/die, heat generation and dissipation have become a more critical factor than ever.
To facilitate the dissipation of the heat generated by a die, an IHS may be affixed to the die and maybe used in conjunction with a heat sink. The IHS is affixed to the die with a layer of thermal interface material that is used to provide some adhesion between the IHS and the die and transfer heat from the die to the IHS. In addition, a heat sink may be placed on top of the IHS with a layer of a thermal interface material placed between the IHS and heat sink to facilitate a limited amount of adhesion and transfer heat from the IHS to the heat sink. The heat sink may have vertical fans extending therefrom to increase the surface area of the heat sink and facilitate the transfer of heat from the IHS to the ambient air. As would be appreciated by one of ordinary skill in the art these heat sinks may take many different forms and may include a small electric fan.
A package may be formed during the assembly process by affixing the die to a substrate and then placing the IHS on top of the die and the heat sink on top of the IHS. The placement of the IHS on top of the die may be accomplished utilizing an industrial robot arm with a grasping tool affixed to the robot arm. The grasping tool may hold the IHS at the edges thereof and place it on top of the die.
Since the die may be made flat and rectangular or square in shape, the IHS is also designed to be flat so that the thermal interface material between the die and the IHS and the thermal interface material between the IHS and heat sink is of a uniform thickness to dissipate heat throughout the die to the IHS and thereafter to the heat sink.
However, because the assembled package contains materials with different coefficients of thermal expansion, and because the package is assembled in steps at various temperatures and because temperature gradients exist in a “powered-up” package the IHS will deform so that it no longer remains flat. Once this deformation occurs in the IHS, the thickness of the thermal interface material between the heat sink and the IHS would vary and the IHS would no longer be able to uniformly dissipate heat from the die to the heat sink.
Further, even though a die may be relatively small, the heat generated by a die may not be evenly distributed throughout the die. In other words, hotspots may be seen in relatively small locations of a die where power consumption is high or heat generating circuits are present.
Therefore, what is needed is a device and method that can determine the manner in which an IHS will deform due to either or both physical manipulation of the IHS itself and heat fluctuations caused by powering on and off the die in the package. Further, this device and method should compensate for the warpage seen in the IHS so that the distance between the IHS and heat sink remain approximately constant. Still further, this device and method should compensate for hotspots on a die and provide additional heat dissipating material in an IHS.